New Study
Finds Pesticide Poisoning at Nation’s Schools
(Beyond Pesticides, July 27, 2005) A new study published
in the Journal of the American Medical Association today finds
that students and school employees are being poisoned by pesticide use
at schools and from drift off of neighboring farmlands. The study, “Acute
Illnesses Associated With Pesticide Exposure at Schools” (Vol.
294, No. 4, pp455-465), by Walter A. Alarcon, M.D. (National Institute
for Occupational Safety and Health) et al, analyzed 2593 poisonings
from 1998 to 2002 from three surveillance systems. While the analysis
finds incident rates overall of 7.4 cases per million children and 27.3
cases per million employees, the authors conclude, “[T]hese results
should be considered low estimates of the magnitude of the problem because
many cases of pesticide poisoning are likely not reported to surveillance
systems or poisoning control centers.” The authors recommend that
strategies be adopted to reduce the use of pesticides at school and
reduce drift.

The authors of the
study work for a range of federal and state agencies, including theNational
Institute for Occupational Safety and Health, U.S. Centers for Disease
Control and Prevention; Office of Pesticide Programs, U.S. Environmental
Protection Agency; and state health and environmental agencies in California,
Florida, Louisiana, Michigan, New York, Oregon, Texas, and Washington.
The surveillance data comes from three sources: California Department
of Pesticide Regulation (CDPR) and the Sentinel Event Notification System
for Occupational Risks (SENSOR), and Toxic Exposure Surveillance System
(TESS).

The study finds
that the incidence rates among children increased significantly from
1998 to 2002. Illness of high severity is found in three cases, moderate
severity in 275 cases, and low severity in 2315 cases. Most illness
is associated with insecticides (35%), disinfectants (32%), repellents
(13%), and herbicides (11%). Among 406 cases with detailed information
on the source of pesticide exposure, 281 (69%) are associated with pesticides
used at schools and 125 (31%) are associated with pesticide drift exposure
from farmland.

The authors cite
that the study misses incidents for which medical attention is not sought
or reported to a surveillance system or a poison control center. “Even
when individuals seek medical care, their illness may not be recognized
as pesticide-related, because of the nonpathogomonic nature of the signs
and symptoms and because clinicians receive little training on these
illnesses.”

Overall, insecticides
are associated with 895 illnesses and most often involve the following:
pyrethrins (13%), chlorpyrifos (13%), malathion (9%), and pyrethroids
(5%); Disinfectants are associated with 830 cases and most often involve
the following: sodium hypochlorite (21%), phenol compounds (21%), pine
oil (13%), and quaternary ammonium compounds (10%). Repellents are associated
with 335 illnesses and most often involve the following: naphthalene
(41%), and diethyl toluamide (DEET) (19%). Herbicides are associated
with 279 illnesses and most often involve: glyphosate (36%), 2,4-D (19%),
and pendimethalin (14%).

The analysis can
be further refined by looking at specific surveillance data sources.
For example, when combining the data from the CDPR and SENSOR, which
predominantly report incidents involving adults, the most common active
ingredients associated with poisonings from school pesticide use include
diazinon (insecticide, 23%), sodium hypochlorite (disinfectant, 17%),
chlorpyrifos (now withdraw for use by schools, 14%), quaternary ammonium
compound (disinfectant, 14%), and malathion (insecticide, 5%). The most
common active ingredients associated with poisoning from pesticide drift
include insecticides, fungicides and herbicides: chlorpyrifos (22%),
methamidophos combined with chlorothalonil and propargite (20%), mancozeb
combined with glyphosate (16%), cyfluthrin combined with dicofol (13%),
and malathion (10%).

While the study
looks at acute, or short-term, effects, the study authors note that,
“Repeated pesticide applications on school grounds raise concerns
about persistent low level exposures to pesticides at schools.”
Continuing, the authors state, “The chronic long-term impacts
of pesticide exposures have not been comprehensively evaluated; therefore,
the potential for chronic health effects from pesticide exposures at
schools should not be dismissed. Unfortunately, the surveillance methods
used in our report are inadequate for assessing chronic effects.”
In addition, the authors note that pesticides on school grounds can
be tracked inside school buildings.